Tagged Questions

Assuming one is inside an eruv which generally permits transferring between domains on Shabbat, may one use an umbrella on Shabbat? If not, why not?
Follow-up question: What about other things that ...

Let's say you bought or built your own shlock (rain cover) for your sukkah.
What halachic concerns are there about operating it on Shabbos/Yom Tov?
Might there be problems of boneh (building)? If the ...